Wang T K, Tsui P C, Kuo I C, Chang H
Appl Opt. 1974 Jun 1;13(6):1379-82. doi: 10.1364/AO.13.001379.
A simple method to examine the optical parallelism between planar end faces of a ruby rod is suggested. When the ruby rod is illuminated by an expanded He-Ne laser beam with linear polarization, the interference pattern due to the recombination of the E and O rays at a Polaroid analyzer shows its optical parallelism. This optical parallelism, which depends not entirely on the mechanical wedge angle but also on the equivalent wedge angle produced by lineage, can be employed as a criterion to show whether or not the ruby rod is suitable in an E-ray oscillation laser system.
提出了一种检测红宝石棒平面端面之间光学平行度的简单方法。当用具有线偏振的扩展氦氖激光束照射红宝石棒时，在偏振片分析仪处E光和O光重新组合产生的干涉图样显示出其光学平行度。这种光学平行度不仅取决于机械楔角，还取决于由晶系产生的等效楔角，可用作判断红宝石棒在E光振荡激光系统中是否适用的标准。
